Once called Tanganyika, this region has been an important element in East African trade routes since antiquity. Both a mainland (Tanganyika) and island (Zanzibar) land, it was inhabited by a variety of native peoples. Though Arabs and Persians controlled the area at different times, the land that would become Tanzania eventually fell under Portuguese influence -- at least as far as coastal trade was concerned (they never did colonize the interior sections of the country). By 1506, they claimed the entire coast, although they were driven out by the sultan of Oman about a century-and-a-half later. The Omanis opened up the slave trade, as well as trade in gold, ivory, and gems. During the 19th century, Britain and Germany both cast their eyes on Zanzibar, dividing up the territory such that Zanzibar became a British protectorate and Tanganyika, a colony of German East Africa. During World War I, the British and the Germans clashed here in battle. The League of Nations turned over the region to Britain as a mandate in 1920, and later the United Nations made it a British trusteeship. Independence for Zanzibar was achieved in 1963, but a revolt one year later resulted in the wholesale departure of thousands of Arab citizens (and the deaths of thousands more). Tanganyika became independent in 1961, led by Julius Nyerere. The two countries united as Tanzania in 1964.